Light cavities are often used in applications requiring relatively uniform illumination of an area such as LCD and other backlit display technologies.
Traditional light cavity designs use direct illumination, meaning the light source is positioned on a surface parallel to the output surface. In designs using multiple light sources (e.g. an array or grid of LEDs), any variation in the wavelength or intensity of the light produced by the light sources will be evident at the output surface in the form of “hot spots” and/or other output artifacts indicating poor light output uniformity. In addition, such a configuration places more stringent requirements on the lighting characteristics of the different light sources to reduce the appearance of these artifacts, leading to increased time and cost in manufacturing.
Accordingly, what is needed is a light cavity that improves light output uniformity and allows light sources with a wider range of intensities and wavelengths to be used.